1. Field of the Invention
The present invention relates to a calibration circuit of a semiconductor device and a method of driving the same, and more specifically, the present invention relates to a calibration circuit for a semiconductor device and a method of driving the same, wherein a set-up/hold value can be secured regardless of variations in process, voltage or temperature in such a manner that data are internally input if the set-up/hold value is not compatible with an operating frequency condition, whether the interlock of data and strobe is pass or fail is checked, and delay times are sequentially controlled depending on the check result.
2. Discussion of Related Art
In the process of fabricating a semiconductor device, after the element is formed on a wafer, a tuning work using a fuse option is implemented in order to control an operating margin and an internal operating voltage of a product depending upon variation in process or device, and is package-assembled to finish a single memory unit. Since it is difficult to replicate the operating frequency at which an actual memory operates before package assembly, a set-up/hold value necessary for the interface, such as data, commands, and address pins being an interface channel with the outside, which is held by a single memory unit of a so-called package character is secured by testing the memory at the operating frequency at which an actual memory device operates after the package assembly. The set-up/hold value is an indispensable condition that must be secured in order to guarantee high speed in an integrated circuit that transmits data or information through a data bus line.
FIG. 10 is a block diagram for explaining a calibration circuit of a semiconductor device in the prior art.
A data input buffer 10 compares data DATA and a reference voltage VREF, and outputs output signals Din and Dinb depending upon the comparison result.
A data strobe buffer 20 transfers a data strobe signal WDSQ to a data latch 30.
The data latch 30 latches the signals Din and Dinb from the data input buffer 10 according to a signal WDQSp from the data strobe buffer 20, and outputs output signals WDin and WDinb.
A write driver 40 writes the data WDin and Wdinb output from the data latch 30 into a memory cell 50 through a data bus.
In the conventional calibration circuit of the semiconductor device constructed above, in the case where a set-up/hold value needs to be tuned, it is required that a difference between the data and the strobe signal that are input to the data latch 30 be calibrated by controlling the delay option of the data input buffer 10, and a circuit be calibrated accordingly by performing a frequency test after package assembly. If variation in process or device occurs, however, these processes have to be performed from the start. Accordingly, there is a disadvantage in that a great deal of time and resources are wasted.